Mechanism for molding material



Aug. 29, 1939. E. N. MEAKIN MECHANISM FOR MOLDING MATERIAL Filed Dec. 27, 1957 11v VENTOR EDGAR N ME/IK/IV HAS A TTORNEY Patented Aug. 29, 1939 UNITED STATES PATENT orica I MECHANISM FOR MOLDING MATERIAL Edgar N. Meakin, San Francisco, Calif.. Application December 27, 1937, Serial No. 181,732

.10 Claims.

practiced and there is on the market today a wide variety of devices for such purpose. In most cases the consolidation of the material is efiected 'by compressing and forcing the same through an apertured die plate or member either by means of rollers or other, pressure-applying applicators which are adapted topass over the surface of the die. 'Heretofore the apertures of the die through which the material passes under pressure have been so disposed, as to lie at right angles to the surface of the die in the event the die comprisesa flat plate or, if the die is in the form of a ring, the apertures are disposed radially therein. During the process of consolidation therefore the pressure-applying. members tend to force the material into the aperturesinsuch manner that compaction is non-uniform.

In this connection the consolidated strings of extruded material are found to be more tightly compacted in that portion which passed along the side of the aperture last approached by the pressureapplying member. It is thus apparent. that the direction of the pressure as applied to the material by the pressure members lies not coincident with the axis of the aperture but at an angle thereto and therefore the effectiveness of the thrust stress of extrusion is materially affected and efliciency decreased. I

It is therefore an important object of my invention to provide a mechanism capable of producing a uniformly consolidated article of moldable material.

A further object of my invention is the provision of a mechanism for molding material employing an apertured die member and a pressure-applying member wherein the axes of the'die apertures lie substantially coincident with the path of movement of the material under pressure.

Another object of my invention is the provision in mechanism of the-class described of an extrusion die, the apertures of I which are so disposed that thenormal cross-sectional area of the inlet end thereof is greater than the normal transverse cross-sectional area of said aperture.

Still another object of my invention is to provide in such mechanism an extrusion die of such character as to obtain maximum extrusion with a minimum of compressive stress.

The invention possesses numerous additional objects and features of advantage, some'of which, together with the foregoing, will become apparent upon perusal of the following description of my invention. It is to be understood, however, that I do not limit myself -to this disclosure of the species' of' my invention, as I may adopt variant embodiments thereof within the scope of the claims.

Referring to the drawing:

Figure 1 is a fragmentary cross-sectional view 1 of a mechanism incorporating my invention and in which a flat die plate is shown with apertures disposed at an angle to a perpendicular rising from the surface thereof. 1

Figure 2 is a similar view but showing an annular die having apertures disposed non-radially therein.

Broadly stated, the. mechanism of my invention comprises a die member having a surface or face-upon which material may be received for compression. A pressure-applying member is providcd for movement over the face of said die to compress the material thereagainst. The die member is provided with a plurality of apertures, the axis of each of which is disposed at an angle to a perpendicular erected from the surface of the die and so that the path of movement of the material beingcompre'ssed lies substantially co-. incident with such axis. I

In greater detail and with reference to the specific illustrations of mechanism shown in the drawing, my invention comprises a die member 3 which may be formed as a flat plate as shown in Figure 1, or. in the shape of a. ring as shown in Figure 2, and upon which material, 4 in loose form such as meals and mashes or the like may be deposited for compression.

For effecting compression of the material I provide a -pressure-applying member 5 preferably a roller positioned adjacent the die andmovable 40 relative thereto and whichis adapted to. compress and force the material toward the adjacent face of the die and consequently into and through the apertures 6 thereof.

It is to be noted that while I have indicated by directional arrows in each illustration the'passage of the pressure-applying member over the face of the die, yet it is to be understood that the pressure member may be held in a stationary position and the die member moved relative thereto to effect compression of the material, and suchmovement being productive of the same results is contemplatedby me in the operation of the mechanism of my'invention. I

As shown in the drawing'the mass of material being compacted between the die and roller is substantially wedge-shaped. It is obvious that where the wedge angle is sufficiently great the roller will push the loosely grouped particles of material ahead of it. On the other hand, where the wedge angle is sufliciently small the material particles compact without forward motion. There is therefore a critical value where, as the wedge angle becomes smaller, forward motion of the adjacent particles of material ceases. At such instance a particle lyingalong the surface of the die will exert an outward force on the. die, "which force may be resolved-into two components,

' one, apressure force along a line passing perpendicularly through the surface of the die, the

' other, a' frictional force at right angles to the first and along. the surfaceof the die. The direction of the-resultant of these two components represents thedirection inwhic h the particle -,t'ur'es at suclrangle-as tosubstantially conform to, the direction of this resultant force :tends to move; therefore ,1 form ,the die aper- .-.'lIn practice I have found that .with the employment of a flat-,die 'plate suchIas shown in Figure 1, if. each aperture 6 is drilled so that the axis 1 thereof intersects, at the point of closest approachpf the roller and die, a perpendicular 8 erected from said die at said point so as to form an angle A of the order of 18, highly efficient results are obtained. With a die in the form of a ring such as shown in Figure 2, however, I have found that if=each aperture thereof is so' drilled that its axis 9 intersects a perpendicular l erected from said die, which perpendicular coincides with the radius thereof, so as to form an angle B of the order of 23, best results follow.

It is to be'understood, however, that I do not intend to .limit my invention to the foregoing specific angles of aperture, since I have found that such angles may vary in accordance with different types of materials and that the same may be drilled at angles ranging from to 30 from a perpendicular erected from the surface of the die plate and give very satisfactory results.

Since the apertures pass through the die at other than a right angle to the surface thereof, it is apparent that the cross-sectional area of the inlet end of the aperture is greater than that of the normal transverse cross-section thereof, thus facilitating the entrance of material under pressure'into the aperture to increase capacity. In some cases, however, I may desire to further increase the area of the inlet end of the aperture so as to facilitate conduction of the material into the aperture, and for such purpose I may countersink the same as shown in Figure 1.

I have found by comparison that mechanism constructed in A accordance with my invention possesses many advantages over those devices now on the market, all of which employ die plates or rings having extrusion apertures drilled at an angle coincident with a perpendicular erected from the surface of the die. Not only am I able to consolidate material into strings of uniform texture throughout, but I effect a substantial saving in power consumed and at the same time increase the capacity of the mechanism. In this connection, comparative tests have demonstrated a saving of from 40% to 60% in power'consumed and an increase of approximately 10% in ca.- pacity.

I claim:

1. In mechanism for molding material, two cooperative relatively movable members, the first of which is provided with a relatively smooth surface upon which material may be received for compression by the second of said members upon relative movement therebetween, said first member having a plurality of apertures therein for the passage of material under pressure, and each of said apertures having its axis inclined toward. the force-applying side of said second member.

2. In mechanism for molding material, two cooperative relatively movable members, the first of which is provided with a relatively even surface upon which material may be received for compression by the second of said members upon relative movement therebetween, said first member having a plurality of apertures therein for the passage of material under pressure, and each of said apertures having its axis inclined toward the force-applying side of said second member at an angle of not to exceed 30 with respect to a perpendicular erected from the surface of said first member.

3. In mechanism for molding-material, a die having a planar surface'upo-n which material may be received for compression, a roller advancing over said die for compressing material against said surface, said die having a plurality of apertures therethrough for the passage of material under pressure, and all of said apertures having their axes inclined toward said advancing roller.

4. In mechanism for molding material, a flat die having a planar surface upon which material may be received for compression, a roller advancing over said die for compressing material against said surface, said die having a plurality of apertures therethrough for the passage of material under pressure, and all of said apertures having their axes inclined toward said advancing roller at an angle of not less than 5 nor more than 30 with respect to a perpendicular erected from said planar surface.

5. In mechanism for molding material, a flat die having a planar surface upon which material may be received for compression, a roller advancing over said die for compressing material against said surface, said die having a plurality of apertures therethrough for the passage of material under pressure, and all of said apertures having their axes inclined toward said advancing roller at an angle of the order of 18 with respect to a perpendicular erected from said planar surface.

6. In mechanism for molding material, an annular die ring having a smooth surface of uniform curvature against which material may be received for compression, a roller advancing over said surface for compressing material thereagainst, said die ring having a plurality of apertures therein through which material may pass under pressure, and all of said apertures having their axes inclined toward said advancing roller.

. .2 flat which material may be received for compression, a pressure-applying member advancing over the surface of said die member and adjacent thereto for compressing material thereagainst, said die member having aperatures therethrough for the passage of material under pressure, and each of said apertures having its axis inclined toward said advancing pressure-applying member.

9. In mechanism for molding material, two cooperative relatively movable members, the first of which is provided with a surface upon which material may be received for compression by the second of said members upon relative movement therebtween, said first member having apertures therethrough for the passage of material under pressure, and all of said apertures having their axes inclined toward the forceapplying side of said second member.

10. In mechanism for molding material, two cooperative relative movable members, the first of which is provided with a surface upon which material may be received for compression by the second of said members upon relative movement therebetween, said first mentioned member being provided with extrusion apertures the inlet ends of which are equally spaced in the compression surface thereof, and all of said apertures having their axes inclined toward the force-applying side of said second member.

EDGAR N. MEAKIN. 

